Large Seasonal Modulation of Tides due to Ice Cover Friction in a Midlatitude Estuary
Large Seasonal Modulation of Tides due to Ice Cover Friction in a Midlatitude Estuary
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DOI：
10.1175/jpo-d-11-063.1
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发表时间：
2012-03
影响因子：
3.5
通讯作者：
N. Georgas
中科院分区：
文献类型：
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作者：
N. Georgas
摘要在哈德逊河口连续三个冬季的多个验潮站观测到了明显的潮汐阻尼（潮汐振幅减少50%）和潮汐调制的季节性事件。通过与美国海岸警卫队冰报告的比较，假设这些事件对应于冰浓度的增加和纽约Peekskill北部潮汐哈德逊上游170 km内季节性冰原的发展。使用固定（潮汐谐波）和非固定（小波）分析以及数值模拟，它表明，冰下摩擦是观测到的调制在整个240公里长的河口潮汐环流（水位和电流）的主要原因。上游的Peekskill的冰原边缘，深度平均潮流下的冰盖通过一阶阻尼大大减少，和垂直的冰下的电流剖面成为抛物线。潮汐范围在靠近...
AbstractSeasonal episodes of significant tidal damping (reductions of tidal amplitudes as much as 50%) and tidal modulation were observed in the Hudson River estuary in the course of three consecutive winters from multiple tide gages. Through comparisons with United States Coast Guard ice reports, it was hypothesized that these events correspond with an increase in ice concentration and the development of a seasonal ice field within the upper 170 km of the tidal Hudson north of Peekskill, New York. Using stationary (tidal harmonic) and nonstationary (wavelet) analyses as well as numerical modeling, it is shown that under-ice friction is the primary cause of the observed modulations in tidal circulation (water levels and currents) throughout the 240-km-long estuary. Upstream of the ice field edge at Peekskill, depth-averaged tidal currents are greatly reduced under the ice cover through first-order damping, and vertical current profiles under the ice become parabolic. Tidal ranges increase near the edge of...